Although the theory of the metal-semiconductor Schottky barrier is some twenty years old, it has received little experimental verification. In the present work, diodes consisting of evaporated gold on n-type silicon surfaces have been fabricated. Reproducibility of diode characteristics (± 10 mV at a given forward current) was obtained by suitable chemical treatments of the surfaces. These diodes have been studied with the major emphasis on the current-voltage characteristics as a function of the doping level of the silicon and temperature.For temperatures greater than 0°C and for Si resistivity above 1 ω-cm, the forward current, in the range studied (< 1 A/cm2), increases exponentially with voltage, the slope being very nearly q/kT (within 10 per cent) as predicted by the simple diode theory. At lower Si resistivities, an excess current component appears, which may be accounted for by space-charge recombination. Indeed, at temperatures below −40°C, the slope is close to q/2kT. From the temperature dependence of the reverse current the recombination-generation centers have been located at 0·31 eV from the center of the band gap.The reverse current is dominated by the excess current component at room temperatures and below. The variation with voltage of high-temperature reverse current can be accounted for by the Schottky effect (effective barrier lowering due to electron-image force).The barrier heights determined from the forward and reverse characteristics are consistent with each other, and also in good agreement with those obtained from capacitance-voltage and photoelectric measurements. The diodes fabricated on 0·1 to 10 ω-cm Si may be characterized by a zero-field barrier height of 0·79 ± 0·02 eV, and a Richardson constant in the range of 10–70 A/cm2 °C2.